Products and services (“items”) are constantly changing and evolving. New information, discoveries and advances across nearly all areas of today's culture naturally lead not only to “brand new” products and services, but also to countless new versions, editions, updates and revisions of existing products and services, such as books, publications, software, technology and everything else in between. Even mattresses evolve and change over time, which changes may or may not be welcome to consumers. While consumers frequently benefit from the plethora of choices and “new and improved” versions of everyday things, all too often consumers may not truly know what exactly has changed, or by how much. This may be particularly true of items in which the difference between a new version and an old item cannot be fully appreciated until the content of the item is determined, such as may be the case with books which undergo periodic revisions.